[ImportantSites] Adding usage metrics.

chrome/android/java/src/org/chromium/chrome/browser/preferences/privacy/ClearBrowsingDataPreferences.java

Index: chrome/android/java/src/org/chromium/chrome/browser/preferences/privacy/ClearBrowsingDataPreferences.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/preferences/privacy/ClearBrowsingDataPreferences.java b/chrome/android/java/src/org/chromium/chrome/browser/preferences/privacy/ClearBrowsingDataPreferences.java
index ae0ad9c391d31a3321fad1a0a5dab00048ca8ebd..d7c6ad5ad054d5221edb791884ed7d19a7d618f8 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/preferences/privacy/ClearBrowsingDataPreferences.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/preferences/privacy/ClearBrowsingDataPreferences.java
@@ -355,9 +355,13 @@ public class ClearBrowsingDataPreferences extends PreferenceFragment
     public boolean onPreferenceClick(Preference preference) {
         if (preference.getKey().equals(PREF_CLEAR_BUTTON)) {
             if (shouldShowImportantSitesDialog()) {
+                RecordHistogram.recordBooleanHistogram(
+                        "History.ClearBrowsingData.ImportantDialogShown", true);
                 showImportantDialogThenClear();
                 return true;
             }
+            RecordHistogram.recordBooleanHistogram(
+                    "History.ClearBrowsingData.ImportantDialogShown", false);

[Theresa, 2016/06/27 20:37:53]

Are we trying to determine how often the dialog shows? If so, should this only
get logged if the feature is enabled? 

[dmurph, 2016/06/28 21:41:22]

Done.

             // If sites haven't been fetched, just clear the browsing data regularly rather than
             // waiting to show the important sites dialog.
             clearBrowsingData(getSelectedOptions(), null);
@@ -395,6 +399,8 @@ public class ClearBrowsingDataPreferences extends PreferenceFragment
     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
+        RecordHistogram.recordBooleanHistogram(
+                "History.ClearBrowsingData.OnCreate", savedInstanceState == null);
         PrefServiceBridge.getInstance().requestInfoAboutOtherFormsOfBrowsingHistory(this);
         getActivity().setTitle(R.string.clear_browsing_data_title);
         addPreferencesFromResource(R.xml.clear_browsing_data_preferences);
@@ -579,6 +585,8 @@ public class ClearBrowsingDataPreferences extends PreferenceFragment
             // Deselected means that the user is excluding the domain from being cleared.
             String[] deselectedDomains = data.getStringArrayExtra(
                     ConfirmImportantSitesDialogFragment.DESELECTED_DOMAINS_TAG);
+            RecordHistogram.recordCount100Histogram(

[Theresa, 2016/06/27 20:37:53]

Since the possible number of deselected domains is low, I think this should use
recordCustomCountHistogram()

[dmurph, 2016/06/28 21:41:22]

Done.

+                    "History.ClearBrowsingData.NumImportantDeselected", deselectedDomains.length);

[Theresa, 2016/06/27 20:37:53]

I don't see a corresponding entry in histograms.xml for this one.

[dmurph, 2016/06/28 21:41:22]

Done.

             clearBrowsingData(getSelectedOptions(), deselectedDomains);
         }
     }